Aluminum magnesium alloy wire suitable for electric arc additive manufacturing

Abstract

The invention relates to the technical field of metal additive manufacturing, in particular to an aluminum magnesium alloy wire suitable for electric arc additive manufacturing. The aluminum-magnesium alloy wire comprises the following components in percentage by mass: 6.5 to 7.5 percent of magnesium Mg, 1.0 to 2.0 percent of manganese Mn, 0.15 to 0.3 percent of scandium Sc, 0.1 to 0.2 percent of zirconium Zr, 0.08 to 0.15 percent of titanium Ti, less than or equal to 0.2 percent of iron Fe, less than or equal to 0.08 percent of silicon Si and the balance of Al and inevitable impurity elements. In the wire preparation process, a thick rod is subjected to multiple times of forging, annealing, drawing, hanging cutting and ultrasonic cleaning, and the solid wire is prepared. The solid wire is fine in grain, good in obdurability and free of plasticity anisotropy after being subjected to electric arc additive forming, and the use requirements of the aerospace field are met.

Description

Technical Field

[0001] The invention relates to the technical field of metal additive manufacturing, and in particular to an aluminum-magnesium alloy wire suitable for arc additive manufacturing. Background Art

[0002] Aluminum alloys have low density, good machinability and strong plasticity, and are widely used in the aerospace field. At present, large-scale complex aluminum alloy components have become the main load-bearing structural parts in the aerospace field. As aerospace manufacturing develops towards high performance, low cost and high efficiency manufacturing, this puts forward new requirements for the manufacturing technology of large-scale complex aluminum alloy components. Arc additive forming of aluminum alloys has the characteristics of high forming efficiency, short manufacturing cycle and low manufacturing cost, and is particularly suitable for the manufacture of large-scale complex high-performance aluminum alloy components.

[0003] Compared with aluminum-copper alloy (heat-treated strengthened aluminum alloy), aluminum-magnesium alloy is a non-heat-treated strengthened aluminum alloy. After arc additive forming, aging heat treatment can meet the performance requirements, avoiding the problem of component quenching and deformation, and realizing rapid arc additive manufacturing. Therefore, aluminum-magnesium alloy arc additive manufacturing is more suitable for low-cost and short-cycle arc additive manufacturing. Relevant personnel have carried out research on aluminum-magnesium alloy wires specifically for arc additive, but they are all based on the optimization of traditional aluminum-magnesium alloy wires. The wire manufacturing cost is relatively high, and the arc additive forming strength is relatively low, which cannot meet the low-cost and high-performance manufacturing needs of arc additive. For example, Ti+Sc composite is used to strengthen aluminum-magnesium alloy, and Ti replaces the Sc element in Al3Sc to form Al3(Sc x ,Ti 1-x ), although the grain refinement effect can be enhanced, the tensile strength, yield strength and / or elongation of arc-added aluminum-magnesium-scandium alloy components do not meet the manufacturing requirements. Summary of the invention

[0004] The present invention provides an aluminum-magnesium alloy wire suitable for arc additive manufacturing. After arc additive forming, the wire developed by the present invention has a tensile strength greater than 425MPa, a yield strength greater than 295MPa, an elongation greater than 16%, and no plastic anisotropy in the transverse and longitudinal directions, which significantly improves the comprehensive mechanical properties of arc additive manufacturing.

[0005] In the first aspect, an aluminum-magnesium alloy wire suitable for arc additive manufacturing is provided, wherein the composition, by mass percentage, is: magnesium Mg: 6.5-7.5%, manganese Mn: 1.0-2.0%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.2%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest is Al and unavoidable impurity elements.

[0006] In combination with the first aspect, in certain implementations of the first aspect, the composition of the aluminum-magnesium alloy wire in mass percentage is: magnesium Mg: 6.5-7.5%, manganese Mn: 1.0-1.5%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.2%, titanium Ti: 0.08-0.15%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the components of the aluminum-magnesium alloy wire suitable for arc additive manufacturing are as follows in mass percentage: magnesium Mg: 6.5-7.0%, manganese Mn: 1.5-2.0%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.15%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the scandium Sc content is 0.2-0.3%.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the silicon Si content is 0.06-0.08%.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the Sc element and the Zr element in the aluminum-magnesium alloy wire are coupled with each other to form a precipitation phase: Al3(Sc,Zr).

[0011] In combination with the first aspect, in certain implementations of the first aspect, the Ti element in the aluminum-magnesium alloy wire is coupled with the Sc element and the Zr element to form a precipitated phase: Al3(Sc,Ti 1-x ) and Al3(Zr,Ti 1-x ).

[0012] In combination with the first aspect, in certain implementations of the first aspect, the aluminum-magnesium alloy wire has Al3 (Sc, Zr) phase precipitated between grains in a deposited state, with a size of 3 to 3.5 μm.

[0013] In combination with the first aspect, in certain implementations of the first aspect, 9. The aluminum-magnesium alloy wire according to claim 8 is characterized in that a secondary Al3(Sc, Zr) phase with a size of 30±5 nm is precipitated in the grain of the aluminum-magnesium alloy wire after aging heat treatment.

[0014] In a second aspect, a method for preparing an aluminum-magnesium alloy wire as described in any one of the implementations of the first aspect is provided, comprising:

[0015] Aluminum-magnesium alloy thick bars with a diameter of less than 40 mm are subjected to 6-8 times of rapid forging, each forging amount reaches 80%-85% of the original, and uniform annealing is performed at the same time;

[0016] The forged solid wire is passed through a sizing die for drawing;

[0017] The prepared solid wire material Φ1.28 mm is subjected to peeling treatment with a peeling thickness of 0.06-0.1 mm to remove the oxide film;

[0018] The solid wire is subjected to ultrasonic cleaning for 10-15 minutes, and then dried to obtain an aluminum-magnesium alloy wire.

[0019] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:

[0020] 1. The aluminum-magnesium alloy wire of the present invention has fine grains, uniform composition, high wire strength, and is suitable for arc additive manufacturing.

[0021] 2. The aluminum-magnesium alloy wire described in the present invention fully considers the non-equilibrium physical metallurgical behavior of arc additive manufacturing, takes into account the coupling effect of various solid solution strengthening matrix elements and grain refining elements, reduces the quality control requirements of aluminum alloy smelting, and is more conducive to industrial production.

[0022] 3. The aluminum-magnesium alloy wire of the present invention, after arc additive forming and aging heat treatment, has a tensile strength greater than 425 MPa, a yield strength greater than 295 MPa, an elongation greater than 16%, and no transverse and longitudinal plastic anisotropy, and is suitable for arc additive manufacturing of high-performance aerospace components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the microstructure of aluminum-magnesium-scandium alloy arc additive manufacturing. (a) is the micronized Al3(Sc, Zr) precipitation phase at the grain boundary of the deposited sample, and (b) is the micronized Al3(Sc, Zr) precipitation phase at the grain boundary and the secondary precipitation phase Al3(Sc, Zr) precipitated in the grain after aging heat treatment. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The invention provides an aluminum-magnesium alloy wire suitable for arc additive manufacturing. The alloy wire comprises, by mass percentage, 6.5-7.5% magnesium Mg, 1.0-2.0% manganese Mn, 0.15-0.3% scandium Sc, 0.1-0.2% zirconium Zr, 0.08-0.18% titanium Ti, ≤0.2% iron Fe, ≤0.08% silicon Si, and the rest being Al and unavoidable impurity elements.

[0026] In a preferred embodiment, the components of the aluminum-magnesium alloy wire suitable for arc additive manufacturing are as follows by mass percentage: magnesium Mg: 6.5-7.5%, manganese Mn: 1.0-1.5%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.2%, titanium Ti: 0.08-0.15%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

[0027] In a preferred embodiment, the components of the aluminum-magnesium alloy wire suitable for arc additive manufacturing are as follows by mass percentage: magnesium Mg: 6.5-7.0%, manganese Mn: 1.5-2.0%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.15%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: 0.06-0.08%, and the rest are Al and unavoidable impurity elements.

[0028] In a preferred embodiment, the components of the aluminum-magnesium alloy wire suitable for arc additive manufacturing are as follows by mass percentage: magnesium Mg: 6.5-7.0%, manganese Mn: 1.5-2.0%, scandium Sc: 0.2-0.3%, zirconium Zr: 0.1-0.15%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: 0.06-0.08%, and the rest are Al and unavoidable impurity elements.

[0029] The present invention provides an aluminum-magnesium alloy wire suitable for arc additive manufacturing, which can be prepared from a thick rod according to the following steps.

[0030] First, the thick rod with a diameter less than 40mm is subjected to 6-8 times of rapid forging, each time the forging amount reaches 80%-85% of the original, and uniform annealing is performed at the same time.

[0031] Second, the forged solid wire is drawn through a sizing die.

[0032] Third, the prepared solid wire material Φ1.28 mm is peeled with a peeling thickness of 0.06-0.1 mm to remove the oxide film.

[0033] Fourth, the solid wire is subjected to ultrasonic cleaning for 10-15 minutes and then dried.

[0034] The aluminum-magnesium alloy wire suitable for arc additive manufacturing provided by the present invention can meet the application of arc additive manufacturing in the military field.

[0035] Compared with the prior art, the present invention provides an aluminum-magnesium alloy wire suitable for arc additive manufacturing, which has the following obvious effects: the Mg element used in the present invention is a matrix solid solution strengthening element. When the Mg content is less than 6.5%, in arc additive forming, the molten pool temperature can reach 3000°C, and the Mg element burns a large amount, making it difficult to play a role in solid solution strengthening of the matrix; when the Mg content is greater than 7.5%, it is difficult for excessive Mg elements to be dissolved into the matrix, which can easily lead to the formation of thermal cracks on the matrix grain boundaries, increase the risk of cracking during arc additive forming, and reduce mechanical properties. The range used in the present invention has good processability and optimal strengthening effect.

[0036] The Mn element used in the present invention can play a role in matrix solid solution strengthening and grain refinement. When the Mn content is less than 1%, under the ultra-fast melting and cooling of arc additive manufacturing, the Mn element mainly plays a role in matrix solid solution strengthening and cannot play a role in grain refinement; when the Mn content is greater than 2%, the excess Mn element cannot be completely dissolved into the aluminum alloy matrix and form submicron Al6Mn particles to refine the grains, which can easily cause Mn to form microcracks on the matrix grain boundaries, reducing the mechanical properties of arc additive manufacturing components. The range described in the present invention can avoid the above problems and has the best strengthening effect.

[0037] The Ti element used in the present invention plays a role in metamorphic nucleation, improving the undercooling degree at the interface front of the aluminum alloy melt pool in arc additive manufacturing, thereby refining the grains. At the same time, the Ti element is coupled with the Sc element and the Zr element to form micron and submicron precipitates (Al3(Sc,Zr), Al3(Sc,Ti 1-x ) and Al3(Zr,Ti 1-x ) phase), which has the effect of comprehensively refining the matrix grains. At the same time, the Ti element can change the morphology of the interlayer precipitation phase (the precipitation phase containing Mn, Fe, and Si elements), reduce the agglomeration of the precipitation phase, improve the interlayer structure, and enhance the uniformity of the mechanical properties of the arc additively formed components.

[0038] Excessive Si elements will increase the precipitation of interlayer phases and reduce mechanical properties. The Si element used in the present invention is an impurity element with a content of 0.06-0.08%. Compared with the prior art, when the Si element content is slightly increased, adding a small amount of Ti element can inhibit its precipitation phase and improve the mechanical properties of the component. In addition, the increase in the range of Si elements reduces the quality control requirements of the aluminum alloy smelting process, which is more conducive to industrial production.

[0039] Example 1

[0040] The invention discloses an aluminum-magnesium alloy wire suitable for arc additive manufacturing. The alloy element composition is as follows by mass percentage: magnesium Mg: 6.5%, manganese Mn: 1.0%, scandium Sc: 0.2%, zirconium Zr: 0.1%, titanium Ti: 0.1%, iron Fe: 0.2%, silicon Si: 0.08%, and the rest are Al and unavoidable impurity elements.

[0041] Example 2

[0042] The invention discloses an aluminum-magnesium alloy wire suitable for arc additive manufacturing. The alloy element composition is as follows by mass percentage: magnesium Mg: 7.0%, manganese Mn: 1.5%, scandium Sc: 0.2%, zirconium Zr: 0.15%, titanium Ti: 0.15%, iron Fe: 0.2%, silicon Si: 0.06%, and the rest are Al and unavoidable impurity elements.

[0043] Example 3

[0044] The invention discloses an aluminum-magnesium alloy wire suitable for arc additive manufacturing. The alloy element composition is as follows by mass percentage: magnesium Mg: 7.5%, manganese Mn: 1.5%, scandium Sc: 0.3%, zirconium Zr: 0.2%, titanium Ti: 0.15%, iron Fe: 0.2%, silicon Si: 0.08%, and the rest are Al and unavoidable impurity elements.

[0045] Comparative Example 1

[0046] The alloy element composition in the comparative example is as follows by mass percentage: magnesium Mg: 6.0%, manganese Mn: 1.0%, scandium Sc: 0.25%, zirconium Zr: 0.2%, titanium Ti: 0.1%, iron Fe: 0.2%, silicon Si: 0.08%, and the rest are Al and unavoidable impurity elements.

[0047] The wires with a diameter of 1.2 mm were prepared in Comparative Example 1, Example 1, Example 2 and Example 3 respectively as raw materials, and arc additive manufacturing equipment was used to form components. The forming parameters were as follows: wire dry wire elongation 12 mm, argon gas flow rate 25 L / min, current 130 A, wire feeding rate 9.5 m / min, deposition rate 8 mm / s, layer thickness 4 mm, overlap rate 55%, and interlayer temperature 50°C. Figure 1 As shown in (a), the size of the fine Al3(Sc, Zr) precipitated phase of the deposited sample of Example 1 is about 3 to 3.5 μm, which can significantly refine the grains, and the grain diameter is about 32±5 μm. Figure 1 As shown in (b), after aging heat treatment, the secondary Al3(Sc, Zr) precipitates in the grains are evenly distributed, with a size of about 30±5nm, strongly pinning the grain boundaries, inhibiting recrystallization and preventing grain growth. As shown in Table 1, after aging heat treatment, the mechanical properties of aluminum-magnesium alloy arc additive forming are significantly improved and there is no plastic anisotropy.

[0048] Table 1 Comparison of strength and toughness of aluminum-magnesium-scandium alloy arc additive manufacturing

[0049]

[0050]

[0051] As shown in Table 1, the mechanical properties of the components manufactured by arc additive manufacturing using the aluminum-magnesium alloy wire prepared by the present invention are low and there is plastic anisotropy. After aging heat treatment, the secondary Al3 (Sc, Zr) precipitation phase is evenly distributed in the grains, which can inhibit deformation, form dislocation rings, and significantly improve the strength. At the same time, the Ti element can weaken the interlayer precipitation phase segregation, reduce the risk of cracking, improve the plastic anisotropy, and thus improve the tensile properties of the component.

[0052] Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

Claims

1. A method for arc additive manufacturing of aluminum-magnesium alloy wire, characterized in that: The components in mass percentage are: magnesium Mg: 6.5-7.5%, manganese Mn: 1.0-2.0%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.2%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

2. The aluminum-magnesium alloy wire according to claim 1, characterized in that: The aluminum-magnesium alloy wire has the following components in mass percentage: magnesium Mg: 6.5-7.5%, manganese Mn: 1.0-1.5%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.2%, titanium Ti: 0.08-0.15%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

3. The aluminum-magnesium alloy wire according to claim 1, characterized in that: The composition of aluminum-magnesium alloy wire suitable for arc additive manufacturing is as follows by mass percentage: magnesium Mg: 6.5-7.0%, manganese Mn: 1.5-2.0%, scandium Sc: 0.15-0.3%, zirconium Zr: 0.1-0.15%, titanium Ti: 0.08-0.18%, iron Fe: ≤0.2%, silicon Si: ≤0.08%, and the rest are Al and unavoidable impurity elements.

4. The aluminum-magnesium alloy wire according to claim 3, characterized in that: The scandium Sc content is 0.2-0.3%.

5. The aluminum-magnesium alloy wire according to any one of claims 1 to 4, characterized in that: The silicon Si content is 0.06-0.08%.

6. The aluminum-magnesium alloy wire according to any one of claims 1 to 4, characterized in that: The Sc element and the Zr element in the aluminum-magnesium alloy wire are coupled to each other to form a precipitated phase: Al3 (Sc, Zr).

7. The aluminum-magnesium alloy wire according to claim 6, characterized in that: The Ti element in the aluminum-magnesium alloy wire is coupled with the Sc element and the Zr element to form a precipitated phase: Al3(Sc,Ti 1-x ) and Al3(Zr,Ti 1-x ).

8. The aluminum-magnesium alloy wire according to claim 6, characterized in that: The aluminum-magnesium alloy wire material has Al3 (Sc, Zr) phase precipitated between crystals in a deposited state, and the size of the phase is 3 to 3.5 μm.

9. The aluminum-magnesium alloy wire according to claim 8, characterized in that: After aging heat treatment, the aluminum-magnesium alloy wire material precipitates a secondary Al3 (Sc, Zr) phase in the crystal, and the size is 30±5nm.

10. A method for preparing an aluminum-magnesium alloy wire according to any one of claims 1 to 9, characterized in that: include: Aluminum-magnesium alloy thick bars with a diameter of less than 40 mm are subjected to 6-8 times of rapid forging, each forging amount reaches 80%-85% of the original, and uniform annealing is performed at the same time; The forged solid wire is passed through a sizing die for drawing; The prepared solid wire material Φ1.28 mm is subjected to peeling treatment with a peeling thickness of 0.06-0.1 mm to remove the oxide film; The solid wire is subjected to ultrasonic cleaning for 10-15 minutes, and then dried to obtain an aluminum-magnesium alloy wire.

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